Cisco Systems 2955 Manual De Usuario
Cisco Systems, Inc.
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Q. How is the Cisco Catalyst 2955 similar to other Cisco Catalyst offerings in terms of the software feature set?
A. In addition to supporting all the enhanced image features of the Cisco Catalyst 2950, the Cisco Catalyst 2955
provides software support for additional hardware (relays, dual power intake) configuration, FCS error monitoring,
and MIB support.
Q. Why is the Cisco Catalyst 2955 powered with 24V DC? Do I have options?
A. Most I/O devices run on 24V, making it commonly available on the factory floor. Cisco provides an optional DIN
rail-mountable power converter allowing for 110/220V AC to be used (PWR-2955-AC).
Q. How mechanically robust is the platform?
A. The Cisco Catalyst 2955 meets extreme mechanical conditions, including accelerations of up to 50 g on each of
its axes (trapezoidal) and multiple vibration levels up to 500 Hz using military testing specifications.
Q. How are relays used? Why are they important?
A. The Cisco Catalyst 2955 has two normally open relays that can be associated to different alarm conditions.
Because many industrial control networks are used in motion control processes, there are important safety issues if
a network fails. The relays allow for external alarm systems (generally a light or audible alarm) to be triggered if a
given threshold error condition is reached. The relays can also be associated to other control devices such as a
programmable logic controller (PLC) to launch a “controlled shutdown” for a given alarm condition. A controlled
shutdown allows for a specific sequence of events to be initiated that will not damage or jeopardize the safety of the
equipment or personnel running a given operation.
Only Cisco offers a dual relay system that gives granularity to the alarm output. This allows the user to program a
first initial alarm (yellow light) when a noncritical condition that needs attention is met, and a second alarm (red
light) when the severity of the alarm merits immediate attention. In many scenarios, the equipment will be deployed
by factory floor technicians (electricians) that are not initially familiar with networking monitoring systems or
protocols. The relays allow for a simple and easy-to-use network alarm system.
Q. Will the Cisco Catalyst 2955 Series operate standalone in harsh environments?
A. The Cisco Catalyst 2955 Series physical protection is rated to IP20, the same rating that most factory floor
production equipment have today. In most applications, production equipment (including the Cisco Catalyst 2955
Series) is housed in a NEMA-12 or IP55 enclosure. It is recommended that the Cisco Catalyst 2955 Series be used in
an enclosure with the appropriate rating.
Q. Do Cisco Catalyst 2950 Series switches support Gigabit Ethernet connectivity? Do they support Gigabit Interface
Converter (GBIC)-based uplinks?
A. Cisco Catalyst 2955 Series switches support Gigabit Ethernet connectivity on the WS-C2955T-12 model via fixed
10/100/1000BASE-T uplink ports. The switches do not currently support GBIC or small form-factor plugables (SFPs)
based uplinks.
Q. What kind of network management is available on the Cisco Catalyst 2955 Series switches?
A. In addition to Cisco Cluster Management Suite (CMS) Software, Cisco Catalyst 2955 Series switches provide
extensive management tools using Simple Network Management Protocol (SNMP) network management platforms
such as CiscoWorks.